The present invention relates to a process for halogenating copolymers of an isoolefin and a para-alkylstyrene in the melt phase, and the halogenated copolymers produced by the process. 2. Description of Information Disclosures
The preparation and use of copolymers of styrene and isobutylene are known. See, for example, U.S. Pat. No. 3,948,868; and U.S. Pat. No. 3,145,187.
U.S. Pat. No. 4,074,035 discloses the copolymerization of isobutylene and halomethylstyrene using vinyl benzyl chloride.
Halogenated copolymers of an isomonoolefin having from 4 to 7 carbon atoms and a para-alkylstyrene are disclosed in European patent application 89305395.9 filed May 26, 1989 (Publication No. 0344021 published Nov. 29, 1989 ) .
U.S. Pat. Nos., 4,513,116; 4,548,995 and 4,554,326 disclose processes for the halogenation of polymers in the melt phase in a continuous flow device.
It has now been found that halogenation of copolymers of an isoolefin having from 4 to 7 carbon atoms and a para-alkylstyrene in the melt phase in a continuous flow device produces halogenated copolymers having improved properties.